“I think it’s particularly alarming that they never took any steps to investigate his citizenship,” said attorney Jennie Pasquarella, the ACLU of California’s director of immigrants’ rights. “He claimed he was a citizen over, and over, and over again and nobody took him seriously.”

ICE spokeswoman Lori Haley said Wednesday in an email that the agency cannot release specific information about a U.S. citizens.

“ICE would never knowingly take enforcement action against or detain an individual if there was probative evidence indicating the person was a U.S. citizen,” Haley wrote. “Should such information come to light, the agency will take immediate action to address the matter.”

Also, the ACLU alleged, ICE broke its own policy stating that an arrestee’s claim of citizenship must be promptly investigated. Instead, they ignored Carrillo’s pleas to check his citizenship status, the lawsuit states.

The case is similar to one that happened earlier this year.

Earlier this year, Guadalupe Plascencia, a 59-year-old San Bernardino resident, was detained by immigration authorities for deportation though she was an American citizen. She said she was arrested in March on a bench warrant for failing to testify in a 2007 case in Ontario. ICE said, at the time, the agency would not knowingly detain a U.S. citizen.

Pasquarella said Carrillo’s arrest raises several questions.

On the day of his arrest, Carrillo’s cell phone rang as he was about to enter The Home Depot, the lawsuit said. The caller asked where he was. Carrillo told him, but when he asked who was on the phone, the caller hung up.

A few minutes later, Carrillo received a text message asking him, “Where are u at.” When Carrillo called the number, the person who answered said he was at The Home Depot, but again refused to identify himself, the suit alleges.

When he left the store, agents clad in black vests labeled “POLICE,” asked if he was Sergio Carrillo and said they wanted to ask him some questions, the lawsuit states. He was eventually arrested.

Soon after, an officer in a Homeland Security uniform arrived. Carrillo explained they had the wrong person because he had been a citizen for more than 20 years, the lawsuit states.

Carrillo was taken to an ICE processing center and eventually to the Adelanto Detention Center, where officers also ignored his citizenship claim, the lawsuit alleges. His case was investigated after the family hired an attorney, who emailed a copy of his passport and certificate of citizenship to an ICE agent, the ACLU said. He was then released.

Pasquarella said the ACLU has records showing agents were looking for Carrillo days before his arrest. Agents had brochures from his landscaping business and his cell phone number, she added.

“It was definitely not a question of mistaken identity, but it is bizarre that they went after him in the first place because they certainly didn’t have enough information about his immigration status,” she said. “All they knew was that he was born in Mexico. They had nothing else.”

Paquarella said Carrillo wanted to sue because he felt his rights were violated.

Alejandra Molina writes about immigration, race, and religion for the Southern California News Group. In her decade-long career, she has reported how gentrification has affected downtown Santa Ana, how racism contributes the high black infant death rate, and how President Donald Trump is impacting undocumented communities across Southern California.